How changing your light globes could help get your sleep cycle back in sync

By Erin Van Der Meer| 2 years ago

Blue light-filtering bulbs claim to aid a good night’s rest, but there’s an important trick to using them.

You wake up in the morning feeling exhausted, and promise yourself you’ll get to sleep earlier tonight. But when bedtime rolls around again, you’re wide-awake, alert, and the last thing you feel like doing is turning out the lights. Sound familiar?

It turns out the large amounts of artificial light humans are exposed to in the modern world are messing with our sleep, as neuroscientist Steven Lockley from the Division of Sleep and Circadian Disorders at Brigham and Women's Hospital in Boston explains.

“Humans evolved in a natural light/dark cycle, which tells the brain when we should be awake and when we should be asleep,” Lockley tells Coach.

“If you see light in the night the brain thinks it’s daytime, so it starts to suppress the hormone melatonin, which is the biochemical signal of darkness, making you feel more alert.

“Although all light will have an effect on us, blue light is the most effective at telling the brain it’s daytime.”

Without getting bogged down in physics, blue is the strongest colour on the light spectrum. The screens of our tech devices, lighting in offices and sometimes the lights in our homes are all enriched with significant levels of blue light.

Enter the blue light-filtering light bulb trend: Several brands, including Philips and Lighting Science, offer bulbs that deplete blue light and claim to help you sleep better. But can changing your light bulbs really help you get better shut-eye?

Lockley says any light bulb that emits a yellowish glow, with a correlated colour temperature (CCT) of around 2700-2800K, will help to reduce blue light.

Devices are even worse than TVs because we use them so close to our faces.

“You’re getting a lot of light straight into the eyes, and that light we know has an impact on your biological system.”

And the effects of blue light don’t stop as soon as you put down our phone or shut off your laptop for the night.

“You get less deep sleep if you’ve been exposed to blue-enriched light just before bed, and that lasts for several hours into sleep,” he says.

“It’ll take you longer to fall asleep, and you’ll feel worse the next morning. Studies have shown you don’t get as much recovery from the sleep and that’s because you’re not having as much deep sleep.”

Lockley recommends not using phones, laptops or other devices at least an hour before bed, but ideally shutting them off two to three hours before you want to sleep.

If you must use devices at night, there are software programs available that you can install on your devices to reduce the blue intensity, such f.lux (Lockley says Apple’s Night Shift function doesn’t work as well as other applications).

A group of people went camping for a weekend, where they were not exposed to any screens, flash lights flood lamps or artificial light of any kind.

When they returned, a saliva test revealed their melatonin levels naturally began to rise two hours earlier compared to before the trip, and also subsided earlier the next morning. In other words, they’d reset their body clocks in a matter of days.

However, blue light isn’t all bad news. It’s helpful for during the day in offices, schools, factories, shopping centres and hospitals, mimicking the effects of sunlight so we can feel as awake and alert as possible when we’re forced to be indoors.

“Bright days are just as important as dark nights,” says Lockley. “If you work inside all day get outside as much as you can for a ‘light shower’, at least every few hours.”

It might seem unthinkable not to look at your phone for an hour or two before bed, but simple schedule shifts can make it easier than you think.

Curling up with a book is an obvious choice, but if you’re so time poor that reading is a rare luxury, you can still be productive. Leave things that don’t require a screen, like doing the washing up, putting away clothes, tidying up or writing a to-do list, for the last hour or two before bed. It could even be good for your sex life.